Through
urine we excrete the water dissoluble metabolic products, which retention in the body could harm the health balance. The routine analysis of the urine is consisted of describing the physical and physicochemical characteristics (pellucidity, color, smell, acidity – pH value, relative density), chemical analyses (the examination, aimed to detection of compounds that are not found in the urine of healthy people) and microscopic examination of urine sediments after being centrifuged.

What does the normal urine look like?
The urine of a healthy person is usually clear and has bright yellow or yellow-orange color (comes from the pigments excreted through kidneys). Normal fresh urine has a characteristic smell, similar to smell of beef soup, and can be a bit acid and a bit base (pH value between 4.5 and 8, usually between 5 and 6). Relative density of urine can vary significantly, depending to the quantity and the quantity of water in the body, external temperature and other factors, and usually measures between 1.010 and 1.025. This value can show the state of, so called, concentration ability of kidneys, which is one of the important parameters for the state estimation of this organ.

Regarding the chemical structure of urine, the analyses should determine the quality and quantity of several types of compounds. These are proteins (up to 0.1g/L), glucose (up to 0.8 mmol/L), ketone bodies (metyl-ketone concentration in healthy people is immeasurable), bile pigments (urobilinogen – 7-17 ìmol/L, bilirubin is immeasurable in healthy people), red blood cells (up to 3x106 erythrocytes per liter), hemoglobin, white blood cells (up to 5x106 leukocytes per liter, they signalize an inflammation process) and nitrates (indicator of the bacterial presence in the urinary track, it is not met in healthy people). The sediment of urine may be unorganized (different salts) and organized (cylinders, epithelial cells, leukocytes, erythrocytes, spermatozoids, microorganisms).

When the precaution is needed?

The quantity of proteins in urine (
proteinuria) may vary, depending on numerous factors (physical exhaustion, standing for a long time), but if it exceeds the value of 200 mg in the period of 24 hours, you should visit your doctor, because there is a possibility that kidneys are damaged (glomerulus or, rarely, tubule) or that the proteins are increasingly produced in blood (in some malignant diseases). Caution and consultations with en expert are also necessary if there is
hematuria – the presence of blood, i.e. red blood cells in the urine (
erythrocyturia). This can be found after hard physical work, injury, and also in calculosis and infections of the urinary tract and renal diseases. By analyzing the quality of erythrocytes it is possible to estimate in what level is the bleeding.

Kidney – The basic function of kidneys is to excrete unnecessary and potentially toxic materials from the blood flow of the organism. The process of ultrafiltration in glomeruli prduces so called primary urine, which is further produced, concentrated and turned into the final urine. Kidneys take part in important processes, such as the excretion of the toxic matters and waste products of metabolism, regulation of the balance of water and salt (maintaining the osmotic balance between blood and tissue) and regulation of acid-base balance.

Urine – Urine is a fluid by which organisms excrete waste products of the organism, and externeous harmful materials. A healthy person excretes approximately 1-2 liters of urine per day, 1.5 L in average. The quantity of urine (diuresis) can significantly vary in some diseases. Excretion can be insufficient (oliguria) in renal or cardiac diseases, for instance. Furthermore, complete impossibility of urinating and retention of urine, for example, because of the opstipation of the urinary tract is called anuria. Excretion of abnormally large volumes of urine (polyuria) is usually found in people with diabetes and diabetes insipidus (hormonal disease which disturbs the water balance in organism). Gradimir Joksimovic, MD